▎ 摘　　要

NOVELTY - Preparing hydrogel microneedle patch comprises adding methyl acrylate to the gelatin solution under predetermined temperature conditions for carrying out the reaction, dialyzing the reaction product, freeze-drying to obtain methacryloyl gelatin, pouring the polydimethylsiloxane solution into the microneedle array mold for curing, peeling to obtain a polydimethylsiloxane mold, dispersing methacryloyl gelatin and the photoinitiator in the graphene oxide solution to obtain a prepolymer solution, adding the prepolymer solution to the polydimethylsiloxane mold, crosslinking the methacryloyl gelatin by ultraviolet irradiation, and demoulding. USE - The method is useful for preparing hydrogel microneedle patch, which is useful for extracting the microRNA (miRNA) in the skin interstitial fluid (claimed). ADVANTAGE - The patch: has rapid sampling and excellent swelling rate; exhibits good mechanical strength to allow it to penetrate the stratum corneum with minimal invasiveness; and achieves simultaneous fluorescent detection of miRNAs by combining isothermal catalytic hairpin assembly signal amplification technology. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a hydrogel microneedle patch prepared by above mentioned method.